In translating an image to printed page, the many colors and textures present in a continuous tone image are represented on the printed page by a limited number of inks applied in a specific way so as to approximate the continuous tone image. Various processes by which continuous tone (CT) images are printed to print media include half toning. For example, an image with many colors, as well as dark, light, and mid tones, is represented on print media using, for example, drops of ink on the print media. Color and the representation thereof is created in one way by using frequency modulation (FM) half toning. In FM half toning, or screening, the greater a number of drops of ink in an area of print media, the darker the perceived color. The fewer the number of drops of ink in an area of the print media, the lighter the color.
To create an image to be printed, such as a bit map (BMP) image, the image is created using various patterns of inks of different colors, applied to the print media according to the printing process, such as FM or amplitude modulation (AM) half-toning. Half toning is accomplished in modern printers and systems using digital filters or screens. Screening is typically done with a raster image processor (RIP), which screens a CT image with a screening cell to create the BMP image that is to be printed.
In an ink-jet printer configuration, printing the drops of ink to the print media is done as precisely as possible so as to create a printed image as close to the original CT image as is possible. However, printing is typically accomplished in many passes of a moving print head moving over the media, or of the moving print media under a stationary print head, or the like. In such a printing process, errors such as mechanical registration and translation errors can and do occur. As the sizes of print drops and the pitch, or distance, between dots decreases, such errors become more noticeable.
For the reasons stated above, and for other reasons that will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for alternative methods and apparatus for printing an image to a print substrate.